LED devices can be manufactured in a variety of configurations, many of which incorporate one or two conductive metal wires connecting a semiconductor or LED die to electrodes at the base of a substrate. Care must be exercised when handling the devices because bonding points of the wires to the electrodes and/or the LED die can easily be damaged. LED die are typically encapsulated with a transparent material or encapsulant which serves to protect the die and wire bonds from physical damage.
LED devices are typically characterized by performance characteristics such as brightness and emission distribution. With the proper selection of transparent material, an encapsulant can be used to increase brightness of an LED device by increasing the amount of light extracted from the LED die. Another way to increase brightness is to attach a lens having a curved outer surface to the LED die such that the two are optically coupled. Modification of the shape of outer surface of the lens is useful for making LED devices having modified emission distributions, for example LED devices having collimated emission distributions or side emitting distributions.
There is a need for new fast, efficient, and low cost methods for manufacturing LED devices having lenses designed to improve efficiency and/or having designed emission distributions.